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Full-Text Articles in Life Sciences

Comparative Energetics Of Mammalian Thermoregulatory Physiology, Ana M. Breit May 2023

Comparative Energetics Of Mammalian Thermoregulatory Physiology, Ana M. Breit

Electronic Theses and Dissertations

Endothermy allows species to decouple body temperature from environmental
temperatures but does not equate to endothermic species maintaining those constant temperatures. Instead, heterothermy fluctuating body temperatures, both in and outside of torpor is common and allows endotherms to expand the limits of thermoneutrality. Thermolability is likely to be more common in the tropics and subtropics, where species live within or above their thermoneutral zone. My dissertation research focused on the heterothermic-homeothermic continuum, specifically quantifying where on the continuum different species fall at certain times and why those species have evolved to be at those points. I quantified the thermal profile …


The Potential For Dickeya Dianthicola To Be Vectored By Two Common Insect Pests Of Potatoes, Jonas K. Insinga Dec 2019

The Potential For Dickeya Dianthicola To Be Vectored By Two Common Insect Pests Of Potatoes, Jonas K. Insinga

Electronic Theses and Dissertations

Dickeya dianthicola (Samson) causing blackleg and soft rot was first detected in potatoes grown in Maine in 2014. Previous work has suggested that insects, particularly aphids, may be able to vector bacteria in this genus between plants, but no conclusive work has been done to confirm this theory. In order to determine whether insect-mediated transmission is likely to occur in potato fields, two model potato pests common in Maine were used: the Colorado potato beetle (Leptinotarsa decimlineata Say) and the green peach aphids (Myzus persicae Sulzer). Olfactometry and recruitment experiments evaluated if either insect discriminates between infected and …


Landscape Pattern And Wild Bee Communities In Maine, Brianne Du Clos May 2019

Landscape Pattern And Wild Bee Communities In Maine, Brianne Du Clos

Electronic Theses and Dissertations

Commercial production of lowbush blueberry (Vaccinium angustifolium Aiton) in Maine relies primarily on managed honeybee hives; however, naturally occurring wild bees are more efficient pollinators of the crop. Wild bees have short foraging distances and must nest near crop fields to provide pollination services. After crop bloom, the surrounding landscape must provide sufficient forage to maintain wild bee populations for the remainder of the growing season. Lowbush blueberries in Maine are produced in a mixed-use landscape with two distinct landscape contexts. Here, we document bee communities and habitat resources (nesting and floral) in power line rights-of-way and eight land …


Divergent Responses Of Larval And Juvenile Blue Mussels To Low Salinity Exposure, Melissa A. May May 2017

Divergent Responses Of Larval And Juvenile Blue Mussels To Low Salinity Exposure, Melissa A. May

Electronic Theses and Dissertations

In this study, we compared the osmotic stress response of larval and juvenile blue mussels (Mytilus edulis) at the transcriptomic, metabolomic, and whole organism levels. Blue mussels inhabit coastal areas, where they face climate-induced reductions in nearshore salinity. Despite their ecological and economic importance, scientists do not fully understand the underlying transcriptomic and cellular mechanisms of the osmotic stress response in blue mussels or how the ability to respond to stress changes throughout development. Blue mussels spend the first weeks of life developing through several larval stages in the plankton. These early life history stages are more vulnerable …


Measuring Fertilization In Populations Of Sea Scallop (Placopecten Magellanicus): Developing And Testing Methods In The Laboratory And Field, Skylar Bayer May 2017

Measuring Fertilization In Populations Of Sea Scallop (Placopecten Magellanicus): Developing And Testing Methods In The Laboratory And Field, Skylar Bayer

Electronic Theses and Dissertations

Most marine organisms are broadcast spawners, releasing their sperm and eggs into the water column. Methods of measuring in situ fertilization have proven successful with a few model species, which are reviewed in my introductory chapter. However, many commercially exploited species, such as the sea scallop Placopecten magellanicus, have been neglected. Sea scallop populations have greatly increased from fishing closures, but the mechanism behind this response is uncertain, particularly in regard to fertilization. In this dissertation I developed a methodology of measuring fertilization success and spawning events of P. magellanicus, tested it in laboratory and field settings, and …


Roles Of Siphon Flows In Suspension Feeding, Kevin Du Clos Dec 2016

Roles Of Siphon Flows In Suspension Feeding, Kevin Du Clos

Electronic Theses and Dissertations

Benthic marine suspension feeders provide an important link between benthic and pelagic ecosystems. The strength of this link is determined by suspension-feeding rates. Many studies have measured suspension-feeding rates using indirect clearance-rate methods, which are based on the depletion of suspended particles. Direct methods that measure the flow of water itself are less common, but they can be more broadly applied because clearance-rate measurements are affected by properties of the cleared particles. We present pumping rates for three species of suspension feeders, the clams Mya arenaria and Mercenaria mercenaria and the tunicate Ciona intestinalis, calculated using a direct method …


Sources Of Ecologically Important Trait Variation In Mosquitofish (Gambusia Affinis And Gambusia Holbrooki), Heather Ann Arnett Apr 2016

Sources Of Ecologically Important Trait Variation In Mosquitofish (Gambusia Affinis And Gambusia Holbrooki), Heather Ann Arnett

Electronic Theses and Dissertations

The study of contemporary evolution and eco-evolutionary dynamics is classically defined in terms of genetic evolution, but the actual suite of processes driving contemporary trait change is likely much more complex than often credited. This dissertation considers additional mechanisms of trait change that might be important to an emerging model system for study of contemporary evolution and eco-evolutionary dynamics. Specifically, the research focuses on phenotypically plastic and demographic trait variation in Eastern and Western Mosquitofish (Gambusia affinis and G. holbrooki) facing the major ecological gradient of predation risk. Plasticity experiments employed a common-garden rearing design to manipulate fish …